Improvement in annealing and polishing sheet-iron



UNITED STATES PATENT OFFICE.

JOSIAH W. ELLS, OF PITTSBURG, PENNSYLVANIA.

IMPROVEMENT IN ANNEALING AND POLISHING SHEET-IRON.

Specification forming part of Letters Patent No. 48,91 S, dated July 25,1865; antedated July 12, 1865.

To all whom it may concern:

Beit known that I, JosIAH W. ELLs, of the city of Pittsburg, in thecounty of Allegheny and State of Pennsylvania, have invented a new andImproved Method or Process ot' Annealing and Polishing Sheet-Iron; and Ihereby declare that the following isa full, clear, and exact descriptionthereof, reference being had to the accompanying drawings, forming partof this speciiication, and to thc letters of reference marked thereon.

The nature of my invention consists in annealing and polishing sheets ofiron by placing them looselyin a tight cast-iron box or muie with scalesor oxide of iron, animal.- charcoal, coke, lime, or other`pdecagbomnaiaing and cutting/@'eigdimpating stifticient mtiontofthewlxor muffle while in the furnace to agitate the sheets of iron to such anextent as will polishvthem by the attrition of the annealing and cuttingagencies during the operation of heating and cooling,whereby they aregiven the peculiar mottled and polished appearance of Russia sheet-iron.

To enable others to understand my improved method or process, I willproceed to describe the mode of operation by reference to the ac-'companyingdrawiugs For this purposeI construct a reverberatory furnaceof brick, and o which- Figure l represents a longitudinal verticalsection. Fig. 2 represents a transverse longitudinal section.

This furnace resembles in shape and construction those of a similarcharacter already in use; but in order to accomplish the purpose forwhich it is intended, in addition to the damper, grate,and otherappendagesincident to such furnaces, I construct a large door, P, Fig.l, at the top, capable of being opened or closed, as the operation mayrequire. Just beneath this door, immediately in the body of the furnaceA, and transverse thereto, I have suspended on trunnions H H, Fig. 2, alarge castiron box, B, resting in appropriate bearings F F, Fig. 2, andon which it can easily be turned. This box, during the working ofthefurnace, is closed by a tight-fitting lid, E, Fig. l, held iu place byany mechanical contrivance that will answer the end.

The operation is as follows: Sheets of iron of a good quality are cutsomewhat smaller than the inside of the box, so as to allow of a littleplay; but before placing them in the box the bottom is to be covered tothe dept-l1 of one inch or more with a composition formed by mixing onepart of pulverized iron-ore with eight parts of limeand`ortrtwlfin:gil-cigar-n calprefere'iiee"beiggiie that iron orewh'icllias'bncebeen used for*an'neli'n'gcastiron. One sheet is then laidflat on this mixture. Some of the mixture is then dustewdpver theupperface of the sheet to the deipt'l ofonefourth of an inch, and a secondsheet laid in, and so on alternatelyr until the box is nearly full,whena coat of the mixture, entirely filling up the box, is placed over all.The lid E, Fig. l, is then to be fastened on. After this is done thedoor P, Fig. 1, at the top ofthe furnace A, is closed, a lire introducedand kept up until the sheets are heated to about 8000, or until thescale begins to loosen. A rotary or oscillating motion is then impartedtothe boxby requisite machinery attached to one ofthe trunnions outsideof the furnace. This motion causes the sheets O, Fig. l, to slide one onthe other, and loosen as well as rub ofthe heavy external scale,polishing at the same time the fine scale thatlies closest to the bodyof the iron, While the continual tumbling` and thumping of one sheet onthe other as they turn over in the box produces those-slightinequalities on the surface of theiron somuch admired in the Russiasheet. This motion of the box is to be kept up for several hours, and atthe same degree of heat, until the sheets are thoroughly polished,whenthe furnace is to be closed perfectly tight to exclude the air, the tirewithdrawn, and the furnace allowed to gradually cool. The motion of thebox, however, is carried on until the heat has diminished at leastone-half. The box is then stopped, and all allowed to cool downtogether, which being ascertained, the box is opened, the sheets takenout, cleaned, and straightened, ready for use.

Fig. 3 represents a mere modification of the plan for operating the box.Instead of supporting the weight by the trunnions, the box N in thiscase is provided at each end with a flanged wheel, R, which enables thebox to roll coke, lime, or other dccarbonizing and cutting agents, andimparting sufcient motion to the box or mufe While in the furnace toagitate the sheets of iron to such an extent as will polish them by theattrition of the annealing and cutting agencies during the operation ofheating and cooling, whereby they are given the peculiar mottled andpolished appearance of Rus-ia sheet-iron.

JOSIAH W. ELLS.

Witnesses:

EB. WILLIAMS, Jr., JOHN MCKENNA.

